Stallone will be sentenced on Monday next week after he pleaded guilty to bringing dozens of vials of the restricted drugs into Australia during a tour to promote his film, "Rocky Balboa."

"I made a terrible mistake, not because I was attempting to deceive anyone but I was simply ignorant to your official rules," Stallone said in a letter to Sydney's Local Court, claiming the drugs had been perscribed to him for an unspecified medical condition.

"I feel terrible that my breach of the rules has set a poor example to members of the public, whose opinion I cherish dearly."

Lawyers for the 60-year-old star of the "Rocky" and "Rambo" movie franchises entered the guilty pleas Tuesday on behalf of the actor, who did not appear in court.

Stallone was charged with importing banned substances into Australia after a customs search of his luggage at the start of a three-day visit to Sydney in February revealed 48 vials of the human growth hormone product, Jintropin.

Three days later, Stallone threw four vials of the male hormone testosterone out the window of his Sydney hotel room when customs officials arrived to search it, prosecutor David Agius told the court.

The maximum penalty for bringing Jintropin into Australia without a license is a fine of 110,000 Australian dollars (US$91,500; EURO 67,532) and five years in prison, but Stallone faces a maximum penalty of just A$22,000 (US$18,000; EURO 13,000) on each of the two charges and no jail time because the matter is being heard by a local, not federal, court.

Prosecutors have also asked that Stallone be ordered to pay A$10,000 (US$8,332; EURO 6,153) to cover the cost of the customs investigation.

Stallone's lawyer Phillip Boulten said the actor should be spared a criminal conviction, saying the actor took the hormones for medical reasons he did not specify.

He said Stallone had been taking the drugs under medical supervision for at least six years, and did not realize he was breaking customs laws by bringing them to Australia.

"This is not some back-alley body builder dealing covertly with some banned substance in some sort of secret way," he said. "This was a legitimate medical condition being treated by doctors of the top ranking order in the west coast of the United States."

But Agius said Stallone had demonstrated a "consciousness of guilt" by throwing the testosterone from the hotel. He also questioned why the actor was carrying Jintropin, a human growth hormone product made by Chinese manufacturer GeneScience Pharmaceuticals that has not been approved by the U.S. Food and Drug Administration.

Human growth hormone, a naturally occurring substance that can be replicated synthetically and is used to build muscle mass, is considered a performance enhancing drug in Australia and it cannot be imported without a permit from the national drug regulator, the Therapeutic Goods Administration.

The muscle-building hormones are available in Australia and the United States by prescription to treat specific medical conditions such as hormone deficiency and stunted growth in children.

Human growth hormone is more widely available in the United States, where it has become increasingly sought-after for its anti-aging properties.